Malicious PDF — malware analysis report

Static analysis result for SHA-256 811874a330f0652e…

MALICIOUS

PDF

14.3 KB Created: 2009-11-15 19:41:70 Authoring application: PDF Library 4.3.9 (via PDF Library 3.9.7)
MD5: 75e173d8917578fba3bae8e828299b28 SHA-1: e79a06dbc8cdb2179d1dd62b8743ac9ae0d6028b SHA-256: 811874a330f0652e58e5813d70541fe99849c6da9a782517ff5d424495e408b4
166 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF file was flagged as malicious by multiple heuristics and a machine learning classifier, with ClamAV identifying it as Win.Trojan.Agent-36166. Embedded JavaScript was detected, which is commonly used to download and execute further malicious content. The presence of JavaScript actions and embedded JS streams strongly suggests this is the primary mechanism for payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 4

  • ClamAV: Win.Trojan.Agent-36166 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Trojan.Agent-36166
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • JavaScript action low PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
javascript_obj0007_000.js
c0f9655c726cf8da2525e6fcf837f0fad9227ce8adfe763e717fd9b2de17f0fc
pdf-javascript-stream PDF /JS object 7 at offset 0x1A5 74733 bytes
Detection
ClamAV: Win.Trojan.Agent-36166
Obfuscation or payload: unlikely